AGC -Automatic Gain Control - A circuit for automatically controlling amplifier gain in order to maintain a constant output voltage with a varying input voltage within a predetermined range of input-to-output variation
Aperture - In television optics, it is the effective diameter of the lens that controls the amount of light reaching the photoconductive or photoemitting image pickup sensor.
Aspect Ratio - The ratio of width to height for the frame of the televised picture 4:3 for standard systems, 5:4 for 1K x 1K, and 16:9 for HDTV
Automatic Brightness Control -In display devices, the self-acting mechanism which controls brightness of the device as a function of ambient light.
Automatic Gain Control - A process by which gain is automatically adjusted as a function of input or other specified parameter.
Automatic Iris Lens - A lens that automatically adjusts the amount of light reaching the imager.
Automatic Light Control -The process by which the illumination incident upon the face of a pickup device is automatically adjusted as a function of scene brightness
Bandwidth - The number of cycles per second (Hertz) expressing the difference between the lower and upper limiting frequencies of a frequency band; also, the width of a band of frequencies
Blooming - The defocusing of regions of the picture where the brightness is at an excessive level, due to enlargement of spot size and halation of the fluorescent screen of the cathode-ray picture tube. In a camera, sensor element saturation and excess which causes widening of the spatial representation of a spot light source.
Brightness - The attribute of visual perception in accordance with which an area appear to emit more of less light. (Luminance is the recommended name for the photo-electric quantity which has also been called brightness.)
CCD - See Charge Coupled Device
C Mount - A television camera lens mount of the 16 mm format, 1 inch in diameter with 32 threads per inch.
CCTV - Common abbreviation for Closed-Circuit Television
Charge-Coupled Device CCD - For imaging devices, a self-scanning semiconductor array that utilizes MOS technology, surface storage, and information transfer by shift register techniques.
Contrast - The range of light to dark values in a picture or the ratio between the maximum and minimum brightness values.
Contrast Range - The ratio between the whitest and blackest portions of television image
DDE – Dynamic Data Exchange
Depth of Field - The in-focus range of a lens or optical system. It is measured from the distance behind an object to the distance in front of the object when the viewing lens shows the object to be in focus.
Depth of Focus -The range of sensor-to-lens distance for which the image formed by the lens is clearly focused.
Fiber Optics - Also called optical fibers or optical fiber bundles. An assemblage of transparent glass fibers all bundled together parallel to one another. The length of each fiber is much greater than its diameter. This bundle of fibers has the ability to transmit a picture from one of its surfaces to the other around curves and into otherwise inaccessible places with an extremely low loss of definition and light, by a process of total reflection.
Field - One of the two equal but vertically separated parts into which a television frame is divided in an interlaced system of scanning. A period of 1/60 second separates each field start time.
Field of View - The maximum angle of view that can be seen through a lens or optical instrument.
Focal Length - Of a lens, the distance from the focal point to the principal point of the lens
Focal Plane - A plane (through the focal point) at right angles to the principal point of the lens
Focal Point - The point at which a lens or mirror will focus parallel incident radiation.
ND Filter - A filter that attenuates light evenly over the visible light spectrum. It reduces the light entering a lens, thus forcing the iris to open to its maximum.
Patch Panel - A panel where circuits are terminated and facilities provided for interconnecting between circuits by means of jacks and plugs.
PC – Windows based Personal Computer
Pixel - Short for Picture Element A pixel is the smallest area of a television picture capable of being delineated by an electrical signal passed through the system of part thereof. The number of picture elements (pixels) in a complete picture, and their geometric characteristics of vertical height and horzontal width, provide information on the total amount of detail which the raster can display and on the sharpness of the detail, respectively.
Shutter - Ability to control the integration (of light) time to the sensor to less than 1/60 second; e.g: stop motion of moving traffic.
Signal-to-Noise Ratio - The ratio between useful television signal and disturbing noise or snow
Snow - Heavy random noise.
Spike - A transient of short duration, comprising part of a pulse, during which the amplitude considerably exceeds the average amplitude of the pulse.
TCP – Transmission Control Protocol
TBL – Terminal Block
Test Pattern - A chart especially prepared for checking overall performance of a television system. It contains various combinations of lines and geometric shapes. The camera is focused on the chart, and the pattern is viewed at the monitor for fidelity.
VB – Visual Basic
VDC – Voltage Direct Current
Vertical Resolution - The number of horizontal lines that can be seen in the reproduced image of a television pattern
VES – Vehicle Enforcement System
Zoom - To enlarge or reduce, on a continuously variable basis, the size of a televised image primarily by varying lens focal length.
Zoom Lens - An optical system of continuously variable focal length, the focal plane remaining in a fixed position.